This invention relates to a rail grinding apparatus for grinding the welded joints of railroad rails. More particularly, it relates to a rail grinding apparatus which does not require the exertion of any significant force by the operator of the apparatus.
The rails of modern railroads are usually connected with one another by butt welding. Various butt welding methods are employed, including gas pressure welding, flash butt welding, thermit welding, and enclosed arc welding. FIG. 1 is a side view of two rails 1 which have been connected by conventional butt welding, and FIG. 2 is a cross-sectional view taken along Line II--II of FIG. 1. As shown in these figures, a weld bead is formed around the entire periphery of the joint between the two rails 1. The weld bead extends considerably above the surface of the rails 1, so it must be removed by grinding. Conventionally, the weld bead is removed from the weld joint using a hand grinder. A surface hand grinder is used to grind the top surface 12, while common hand grinders are used to grind the gage corner surfaces 13 and the upper lateral surfaces 14 of the rails 1. Two different types of grinders must be used. These grinders are hereunder collectively referred to merely as "hand grinders".
Furthermore, the contact force between a hand grinder and the surface of the rails 1 must be exerted by the operator of the hand grinder. As it is difficult for an operator to exert a steady contact force, hand grinding often produces irregularities in the surface of the rails 1, and it is difficult to obtain a finished surface having the required surface tolerance of -0.1-+0.3 mm/m. Hand grinding also produces an unpleasant shrill noise, which is objectionable from the standpoint of both the operator of the hand grinder and others working nearby. Furthermore, a hand grinder generates vibrations which are not only fatiguing to an operator and prevent him from working for long periods but which also may cause the operator to develop medical problems, such as Raynaud's phenomenon.